Load development with Magneto Speed chrono

[Keizer09]

I'm curious as to how y'all develop loads using a magneto speed. I just bought one because of its simplicity to set up, but I realize that I can't chrono the loads as I shoot them for accuracy since the harmonics will be affected.

I guess that means I shoot and then chrono the best performing loads after the fact to see the spreads?

Thanks

 

[MJY65]

I'm curious as to how y'all develop loads using a magneto speed. I just bought one because of its simplicity to set up, but I realize that I can't chrono the loads as I shoot them for accuracy since the harmonics will be affected.

I guess that means I shoot and then chrono the best performing loads after the fact to see the spreads?

Thanks

That's what I've started doing with my Oehler 35P. Obviously, it doesn't affect accuracy the way a Magnetospeed does, but it does take time to set up correctly. Especially, if you are sharing the range with others. If I'm working up a load for accuracy, I really don't need to chase maximum velocity. I find the load I like, then chronograph it.

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[RSCOT]

I was using mine while doing OCW testing for my 280 and it was working fine. Then I noticed that the unit had moved to within about a 1/2in of the muzzle so moved it back and re-tightened it which caused a shift in POI. I didn't have it tight enough (was worried about screwing down too much and breaking it). I called and talked to them and they said no problem just make it tight it won't break. They recommend not using it until you have found your load which is what I'm doing now. From what I've read here there isn't much effect on group size, only POI.

 

[Keizer09]

Thanks for the replies. That makes a lot of sense.

 

[Lucks]

I usually use the Magnetospeed initially to find out what loads get me up to the velocity range I am looking for/expecting. Then from there I fine tune it looking for best groups without the magnetospeed on. After that, I put the magnetospeed back on to determine the final velocity of the load I go with.
Honestly though, the magnetospeed hasn't really affected my groups that much other than on my rifles it usually makes me shoot a little high. POI usually shift up .3 - .4 mils with the Magneto on there.
I love the Magnetospeed, good purchase.

 

[dauntedfuture]

Guys that I have talked with that shoot them in HP and F Class say that accuracy is not affected but POI is, so after adjusting into the center there are no issues. they say its helpful when confirming a high or low shot and looking at velocity numbers to confirm/ deny. It also provides them with a good source of velocity data for further load development and testing in a match so they are not burning out a barrel in testing.

 

[svxwilson]

I am new to the Magnetospeed as well. I can attest to the above POI shift. I have not been doing any paper target shooting while I have it on I shoot at some steel gongs as the info I am looking for is strickly from the Magneto. I have been doing a ladder with mine. I load 10-15 powder drops in .2gr increments. For example I loaded up 39-41.6gr of AR-Comp under a 168Gr Amax and shot 2 of those ladders consecutively. I go home and analyze the data and look for the areas that have small consistent accuracy deviations. I found multiple "nodes" or consistent velocity areas. I have not gone back out to verify these nodes on a paper target yet but this is a new way of development for me and am in the beginning stages of it. From what I have read this is a good first step to do, done correctly it is meant to speed up the process and use less powder, bullets, etc to find a node.

 

[KYpatriot]

As has been mentioned in a couple other threads, the magnetospeed definitely affects the POI, almost always moving the impacts away from the bayonet (ie, if the bayo is mounted at 6 oclock on the barrel the impacts typically shift to 12 oclock. Regardless, the effect seems very repeatble and for me at least does not affect group size. Therefore, it should have no impact on load development.

Its too bad that loads that shoot well at 100 often have wide extreme spreads. Load development would be a lot easier if this wasnt the case.

 

[Splat]

I found that it does effect my group size ever so slightly. Last week I went to the range and I was cursing about my groups while using the Magneto. Another guy there that has a Magneto suggested that I take it off because he had the same issue with it on. I was averaging just over MOA at 100 yds shooting 168gr FGMM factory ammo with it on. Taking it off I get .75 MOA and better. While testing hand loads shooting with the MagnetoSpeed, I was getting great SD's but the best SD's didn't produce the best groups... I'm wondering if it has to do with the MagnetoSpeed. I will have to retest those loads without the bayonet and see how it works out.

 

[Twoboxer]

All the above comments about a shift in POI are of course correct . . . but what has been minimized is that a change in strap tension or bayo position can change the changed POI yet again.

Unfortunately . . . as I've learned . . . that type of change can happen at any time, so I make extra rounds at intervals to chrono.

For me, MagnetoSpeed's convenience often makes up for the loss of chrono data on the actual rounds used for load development. YMMV.